Ultrastructural evidence of GABA-ergic inhibition and glutamatergic excitation in the pacemaker nucleus of the gymnotiform electric fish, Hypopomus.
Ultrastructural evidence of GABA-ergic inhibition and glutamatergic excitation in the pacemaker nucleus of the gymnotiform electric fish, Hypopomus.
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裸形电鱼 Hypopomus 起搏核中 GABA 能抑制和谷氨酸能兴奋的超微结构证据。
DOI：
10.1007/bf00240210
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发表时间：
1994
期刊：
影响因子：
--
通讯作者：
Heiligenberg,W
中科院分区：
文献类型：
--
作者：
Kennedy,G;Heiligenberg,W
下垂体髓质起搏器核通过单一指令脉冲触发各电器官放电（EOD）。它由产生节律的电张力耦合“起搏器”细胞和跟随起搏器细胞并刺激电器官的脊髓运动神经元的“中继”细胞组成。起搏器细胞接受间脑预起搏器核复合体的两种输入，一种是gaba能抑制，另一种是谷氨酸能兴奋。另一方面，中继细胞接受两个谷氨酸能输入，一个来自PPn亚核PPn- c，另一个来自丘脑下预备起搏器核（SPPn）。我们通过向预起搏器复合体的特定部位注射HRP标记了到起搏器核的传入信号。通过免疫金标记抗体和网格染色技术，我们证明了GABA和谷氨酸在起搏器细胞核超薄切片标记的突触谱中的免疫反应性。这两种类型的突触分布在起搏器细胞的表面，其中gaba免疫反应性突触显然代表gaba介导的PPn- i的输入，PPn的抑制性细分，以及谷氨酸免疫反应性突触代表PPn的兴奋性细分，PPn- g的输入。仅在中继细胞上发现谷氨酸免疫反应突触。
The medullary pacemaker nucleus ofHypopomustriggers each electric organ discharge (EOD) by a single command pulse. It consists of electrotonically coupled ‘pacemaker’ cells, which generate the rhythm, and ‘relay’ cells, which follow the pacemaker cells and excite the spinal motoneurons of the electric organ. The pacemaker cells receive two inputs from the complex of the diencephalic prepacemaker nucleus (PPn), a GABA-ergic inhibition and a glutamatergic excitation. Relay cells, on the other hand, receive two glutamatergic inputs, one from a subnucleus of the PPn, the PPn-C, and a second from the sublemniscal prepacemaker nucleus (SPPn).We have labelled afferents to the pacemaker nucleus by injecting HRP to specific sites of the prepacemaker complex. By using immunogold-labelled antibodies and en-grid staining techniques, we demonstrated GABA and glutamate immunoreactivity in labelled synaptic profiles of ultra-thin sections of the pacemaker nucleus. The two types of synapses were interspersed on the surfaces of pacemaker cells, with GABA-immunoreactive synapses apparently representing the GABA-mediated input of the ‘PPn-I’, an inhibitory subdivision of the PPn, and glutamate-immunoreactive synapses representing the input of the ‘PPn-G’, an excitatory subdivision of the PPn. Only glutamate-immunoreactive synapses were found on relay cells.